Mechanical behavior and fracture mechanism of red-bed mudstone under varied dry-wet cycling and prefabricated fracture planes with different loading angles

•Evaluated the mechanical behavior and fracture mechanism of red-bed mudstone under dry-wet cycling and prefabricated fracture planes with different loading angles.•Experimental results showed that increasing loading angles led to higher fracture loads, while more dry-wet cycles decreased fracture loads.•Dry-wet cycling caused the expansion of initial microcracks, forming weak layers that affected the main crack morphology and secondary crack distribution.•Acoustic emission count decreased with more dry-wet cycles, and rougher fracture surfaces were observed with increased cycles and loading angles.•Findings contribute to the understanding of red-bed mudstone stability and reliability under dry-wet cycling and prefabricated fracture planes with different loading angles.